Out of concern that (4)
I believe the answer is:
lest
'out of concern that' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lest that I've seen before include "For fear that; in order to prevent" , "For fear that (something happens)" , "To avoid the risk that - we forget?" , "In case" , "In order not to, say forget?" .)